When two electronic devices are connected to a network (e.g., a computer or communication network), data may be transmitted between the two devices over the network using one or more suitable network protocols. For example, in a client-server environment, data may be transmitted between a server and a client over a network to which both the server and the client are connected. Of course, a network may include any number of sub-networks. By transmitting data between the two devices, the two devices may communicate with each other.
Mobile devices such as mobile phones, tablets, and personal computers often communicate through wireless networks provided by cellular carriers. Modern 3G and 4G networks, both CMDA2000-based and GPRS-based, permit simultaneous access of wireless data through the packet-switched portion of its wireless cellular network and voice data through the circuit-switched portion of its wireless cellular network. Additionally, modern wireless cellular networks permit simultaneous communication through the packet-switched data portion of their networks and through their short message service (SMS) channels.